SITE INFORMATION AND CORRESPONDENCE (3)

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EI Dorado Senior Apartments July 27, 1992 Page 3 of 21 ppm. The hexavalent chrome concentrations from after DI extraction was less than .01 mg/f. the four samples with the highest total lead levels (SIA, S1B, S2A, S2B) were analyzed for soluble lead after extraction by the State WET Method. Total lead levels of 90 ppm, 42 ppm, 83 ppm, and 23 ppm yielded extractable concentrations of 3.3 mg/f, 1.6 mg/f, 2.1 mg/f, and 1.3 mg/f, respectively. This indicates approximately 2.5 - 5% of the total lead is extractable by citrate solution. None of the samples exceeded hazardous criteria. January 1992: Mr. Hunt of the County requested that a sample be collected from 18 inches beneath the floor of the Community Building (see Figure) in an area believed to be the former dispenser island. This sample (identified as CH-1) was analyzed for BTEX, total gasoline hydrocarbons, purgeable organic priority pollutants (EPA 8240), and total lead. Analyses of this sample showed no detectable BTEX, gasoline hydrocarbons or purgeable priority pollutants. The sample analysis reported a total lead level of 250 ppm. This sample did not exceed the hazardous criteria for lead. March/April 1992: Based on the total lead level in Sample CH-1 (250 ppm) and beneath the former 300 gallon tank (Sample T5, 43 ppm), Mr. Hunt required both of these samples to be reanalyzed for soluble lead and nickel after a deionized water extraction. Sample CH-1 had been destroyed, however, Sample T5 was nun and exhibited a lead level of .011 mg/f and a nickel level of < .005 mg/f.. Both of these Ievels are below State MCL's for groundwater. April 23, 1992: Based on the inability of reanalyzing CH-1, Mr. Hunt requested that an additional sample be collected at a depth of 48 inches below the floor at the same location. He specifically indicated the sample was to be analyzed for soluble lead using a deionized water extraction. An attempt to reach 48 inches was made by FGL Lab personnel but they could only reach 20 inches, approximately the same depth as the original sample. June 22, 1992: RESNA personnel, utilizing a hand auger, collected a sample from 48 inches below the floor in the original CH-1 borehole. This sample was submitted to A&L Laboratory and analyzed for total and DI soluble lead. I4� The analy s-ind� -ted-a-total lead level of 26.7 ppm and a soluble lead level of less than .05 mg/f.N. he soluble level is below the State MCL for C.072192.RW1 � 0 �Xrew' e, V INV